It is known that rigid display cartons are made which comprise portions which are torn off upon first opening the carton, to allow the packets inside to be seen.
Such a type of carton is known from document U.S. Pat. No. 5924559 which discloses a multiuse carton formed by first and second base panels separated from each other by side walls and end walls to form an interior space in which a plurality of items are arranged in rows. The carton further includes a hinged tear away portion panel for exposing the items in the carton for display.
However, the above-mentioned known type of rigid display cartons are normally made from blanks whose shape make them difficult to machine and, therefore, production of the display cartons necessitates substantial modification to the construction of existing cartoning machines.
The aim of the present invention is to provide a flat blank which is free of the above-mentioned disadvantages and which, in particular, is easily machined and allows the production of a rigid display carton by means of simple modifications to existing cartoning machines.
Accordingly, the present invention provides a flat blank for the formation of a rigid carton for cigarette packets, which is substantially the shape of a parallelepiped. The carton comprises a front wall, a rear wall, two side walls, a lid and a base. The blank has a longitudinal axis and comprises a central part delimited by two longitudinal fold lines which are parallel with the longitudinal axis and two side parts located on opposite sides of the central part. The blank also comprises a set of transversal fold lines, which divide the central part into a first panel which forms the base, a second panel which forms the front wall, a third panel which forms the lid and a fourth panel which forms the rear wall. The second panel is divided into a substantially trapezoidal and a second portion by a pre-weakened tear line. The third panel is divided by a fold line into a first portion adjacent to the second panel and a second portion adjacent to the fourth panel. The side walls comprise two fifth panels located on opposite sides of the first panel and forming the side walls.
The second panel has respective first vertices located on the longitudinal fold lines in contact with the third panel. The blank is characterized in that the pre-weakened line has a central segment which is parallel with the tranversal fold lines, and two side segments that join the central segment to the two first vertices.
The present invention is now described with reference to the accompanying drawings, which illustrate preferred embodiments, of it without limiting the scope of its application, and in which: